Apparatus and method for an excavator

ABSTRACT

An excavator comprises a frame, a boom assembly and a control architecture. The control architecture may include a first actuator, a second actuator, a third actuator, a user input interface, a storage medium having a control algorithm, and a controller configured to execute the control algorithm to: receive a target grade request from one or more of the user input interface and a storage medium; receive a dipper stick position relative to the pivot axis; receive a direction of movement of the dipper stick; determine whether the dipper stick position is outside the pivot axis or inside the pivot axis; and operate the first actuator in automatic mode to automatically adjust the pivot axis height relative to the frame when the dipper stick position and the direction of movement of the dipper stick are within the automatic control region for automatically maintaining a target grade.

CROSS-REFERENCE TO RELATED APPLICATIONS

N/A

FIELD OF THE DISCLOSURE

The present disclosure relates to an apparatus and method for an excavator.

BACKGROUND

The present disclosure relates to automatic or semi-automatic controls in the use of excavators.

Operating an excavator requires skill and experience from the operator in order to properly perform functions such as excavating flat surfaces or grading a precise guide for trenches. Operators may benefit from machine-assisted control to maintain precision without surrendering full control.

SUMMARY

This summary is provided to introduce a selection of concepts that are further described below in the detailed description and accompanying drawings. This summary is not intended to identify key or essential features of the appended claims, nor is it intended to be used as an aid in determining the scope of the appended claims.

An excavator may comprise a frame, a ground-engaging mechanism coupled to the frame and configured to support the frame on a surface. The excavator may also include a boom, a first actuator, a dipper stick, a second actuator, an implement, a third actuator, at least one senor, and a control architecture. The boom may be pivotally coupled to the frame. The first actuator may interconnect the boom and the frame wherein the first actuator is operable to move the boom relative to the frame. The dipper stick may be pivotally coupled to the boom for rotational movement about a pivot axis. The second actuator may interconnect the dipper stick and the boom; and be operable to move the dipper stick about the pivot axis relative to the boom. The implement may be pivotally coupled to the dipper stick. The third actuator may interconnect the implement and the dipper stick wherein the third actuator is operable move the implement relative to the dipper stick. The sensor may sense one of a dipper stick position and a direction of movement of the boom, the dipper stick, and the implement. The control architecture may include a user input interface, a storage medium having control algorithm, and a controller configured to execute the control algorithm. The control algorithm may receive a target grade request, one or more of the user input interface and the storage medium; receive a dipper stick position relative to the pivot axis from the at least one sensor, wherein the dipper stick position is one of inside the pivot axis or outside the pivot axis; receive the direction of movement of the dipper stick relative to the pivot axis from the at least one sensor, wherein the direction of movement of the dipper stick is one of arming away from the pivot axis or arming toward of the pivot axis; and operate the first actuator in an automatic mode to automatically adjust a height of the pivot axis relative to the frame when the dipper stick position and the direction of movement of the dipper stick are within an automatic control region for automatically maintaining a target grade.

The operating mode of the first actuator in an automatic mode may include moving the boom upwards when i) the dipper stick is outside the pivot axis and ii) the dipper stick is arming in; moving the boom upwards when i) the dipper stick is inside the pivot axis and ii) the dipper stick is arming away; moving the boom downwards when i) the dipper stick is outside the pivot axis and ii) the dipper stick is arming away; and moving the boom downwards when i) the dipper stick is inside the pivot axis and ii) the dipper stick is arming in. The controller may also be configured to deactivate the automatic mode of the first actuator when the dipper stick position and the direction of movement of the dipper stick are outside the automatic control region.

The control architecture may be further configured to execute instructions to activate the third actuator in the automatic mode to automatically curl or dump the implement to adjust an angle the cutting edge of the implement engages the surface when the dipper stick position and the direction of movement of the dipper stick are within the automatic control region, the automatic mode maintaining the target grade. This may comprise dumping the implement when the dipper stick is arming in; and curling the implement when dipper stick is arming away. Arming in of the dipper stick comprises extension of the second actuator. Arming away of the dipper stick comprises retraction the second actuator. The controller may further deactivate the automatic mode of the third actuator when the dipper stick position and the direction of movement of the dipper stick are outside the automatic control region.

Maintaining a target grade is sourced from feedback from one or more a global positioning system and a positioning of the dipper stick relative to the frame.

The user input interface may comprise of a first joystick and a second joystick. The first joystick arming away the dipper stick when moved forward and arming in the dipper stick when moved backward. The second joystick curling the implement when moving the joystick to the left and dumping the implement when moving the joystick to the right.

The disclosure also comprises a method for controlling an excavator. The method comprises enabling an automatic mode based on user input with a switch from a user input interface; receiving a target grade request from one or more of the user input interface and a storage medium; receiving a dipper stick position relative to a pivot axis from at least one sensor, wherein the dipper stick position is one or more of inside the pivot axis and outside the pivot axis; receiving a direction of movement of a dipper stick relative to the pivot axis from the at least one sensor, wherein the direction of movement of the dipper stick one of arming away from the pivot axis or arming toward the pivot axis; and activating the first actuator in the automatic mode to automatically adjust a height of the pivot axis relative to a frame based on the dipper stick position and the direction of movement of the dipper stick automatically maintaining a target grade.

These and other features will become apparent from the following detailed description and accompanying drawings, wherein various features are shown and described by way of illustration. The present disclosure is capable of other and different configurations and its several details are capable of modification in various other respects, all without departing from the scope of the present disclosure. Accordingly, the detailed description and accompanying drawings are to be regarded as illustrative in nature and not as restrictive or limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description of the drawings refers to the accompanying figures in which:

FIG. 1 is a side view of an excavator with the boom assembly in multiple positions;

FIG. 2 is a schematic of the control architecture for the embodiment shown in FIG. 1;

FIG. 3 is a side view of the implement maintaining a target grade as the implement engages the surface;

FIG. 4A is a schematic of an excavator arming in;

FIG. 4B is a schematic of an excavator arming away;

FIG. 5 is a schematic of the user input interface referred to in FIG. 2;

FIG. 6 is a top view of an excavator shown an embodiment of automatic control region; and

FIG. 7 is a flowchart of an algorithm for operating a boom assembly and/or implement with the control architecture for the embodiment shown in FIG. 1.

DETAILED DESCRIPTION

The embodiments disclosed in the above drawings and the following detailed description are not intended to be exhaustive or to limit the disclosure to these embodiments. Rather, there are several variations and modifications which may be made without departing from the scope of the present disclosure.

As used herein, unless otherwise limited or modified, lists with elements that are separated by conjunctive terms (e.g., “and”) and that are also preceded by the phrase “one or more of” or “at least one of” indicate configurations or arrangements that potentially include individual elements of the list, or any combination thereof. For example, “at least one of A, B, and C” or “one or more of A, B, and C” indicates the possibilities of only A, only B, only C, or any combination of two or more of A, B, and C (e.g., A and B; B and C; A and C; or A, B, and C).

As used herein, the storage medium comprises electronic memory, nonvolatile random access memory, an optical storage device, a magnetic storage device, or another device for storing and accessing electronic data on any recordable, rewritable, or readable electronic, optical, or magnetic storage medium.

As used herein, the term “controller” is a computing device including a processor and a memory. The “controller” may be a single device or alternatively multiple devices. The controller may further refer to any hardware, software, firmware, electronic control component, processing logic, processing device, individually or in any combination, including without limitation: application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.

As used herein, the location-determining receiver may comprise a Global Positioning System Receiver (GPS) or any satellite navigation receiver for providing: (1) position data, elevation data, attitude, roll, tilt yaw, motion data, acceleration data, velocity, or speed data for a vehicle or its components, such as the boom, dipper stick, and implement. For example, the location-determining receiver may comprise a satellite navigation receiver with a secondary receiver or transceiver for receiving a differential correction signal to correct errors or enhance the accuracy of position data from received satellite signals.

FIG. 1 illustrates a side view of an excavator 100 in varying positions. The excavator may comprise of a frame 105, a ground-engaging mechanism 110 coupled to the frame 105 and configured to support the frame 105 on a surface 115. Generally, an upper portion 140 of the frame 115 may be pivotally mounted on to an undercarriage 145 by means of a swing pivot. The undercarriage 145 may be coupled to the ground-engaging mechanism 110, wherein the ground-engaging mechanism 110 may comprise a pair of tracks or wheels for moving along the surface. The frame 105 may include an operator cab 150 (although not required for remotely operating an excavator) in which the operator controls the excavator 100 through a user input interface 155 (also shown in FIG. 5). The user input interface 155 may include control levers, control pedals, buttons, and a graphical display screen. A boom 160 may be pivotally coupled to the frame 105. A first actuator 165 may interconnect the boom 160 and the frame 105. The first actuator 165 may be operable to move the boom 160 relative to the frame 105. A dipper stick 170 may be pivotally coupled to the boom 160 for rotational movement about a pivot axis 175. A second actuator 180 may interconnect the dipper stick 170 and the boom 160. The second actuator 180 may be operable to move the dipper stick 170 about the pivot axis 175 relative to the boom 160. An implement 185 may be pivotally coupled to the dipper stick 170. A third actuator 190 may interconnect the implement 185 and the dipper stick 170. The third actuator 190 may be operable to move the implement 185 relative to the dipper stick 170. At least one sensor 195 may be operable to sense one or more of a position (exemplary shown as a dipper stick position 230 in FIG. 2) or a direction of movement (shown as an exemplary dipper stick direction of movement 235 in FIG. 2) of one or more of the boom 160, the dipper stick 170, and the implement 185. In one example, the boom assembly 163, comprising of the boom 160, the dipper stick 170 and the implement 185, may be digging a trench for pipe-laying where the uniformity and grade of the surface 115 in the trench ensures proper pipe-laying. FIGS. 1 and 3 show the boom assembly of the excavator moving from left to right, wherein the cutting edge 200 of the implement 185 maintains constant contact with the surface 115 to achieve a target grade 205 (shown in FIG. 2).

Now turning to FIGS. 2 and 7, the excavator 100 may comprise of a control architecture 210 including a user input interface 155, a storage medium 125 having a control algorithm stored therein, and a controller 130 configured to execute the control algorithm. In a first step 710, after the user enables automatics mode 220 the controller 130 may in a next step 720, execute the control algorithm upon receiving instructions that activation requirements 215 are met. Activation requirements 215 may comprise one or more of the operator enabling automatic mode 220 (e.g a switch, screen selection, knob) and the excavator 100 meeting thresholds for hydraulic pressure, engine speed, etc. In some embodiments, the operator may not be required to physically enable automatics mode 220 through a switch. Automatics mode 220 may be enabled directly by meeting the threshold requirements 280 for hydraulic pressure, engine speed, etc. Thresholds requirements 280 may include excavating system requirements and may further include entering an automatic control region 265, described in more detail below. The control algorithm may further be configured to receive a target grade request 225 from one or more of the user input interface 155 and the storage medium 125; receive a dipper stick position 230 relative to the pivot axis 175 from the at least one sensor 195 wherein the dipper stick position 230 is one of inside the pivot axis 175 or outside the pivot axis 175; receive a direction of movement 235 of the dipper stick relative to the pivot axis 175 from the at least one sensor 195 wherein the direction of movement 235 of the dipper stick 170 is one of arming away 240 from the pivot axis 175 or arming in 245 toward of the pivot axis 175; and activate the first actuator 165 in an automatic mode 220 to automatically adjust a height of the pivot axis 175 relative to the frame 105 based on the dipper stick position 230 and the direction of movement 235 of the dipper stick 170 for automatically maintaining a target grade 205. Note that when mentioning the height of the pivot axis 175 relative to the frame 105 is representative of a multitude of ways of measuring the relative position of the pivot axis 175. For example, the height of the pivot axis 175 may also be measured through linkage kinematics, relative to the ground surface 115, or relative to the ground-engaging mechanism 110, to name a few.

Maintenance of the target grade 205 may be sourced from feedback from one or more of a location determining receiver 135 and a positioning of the boom assembly 163 (or its components) relative to the frame 105.

Receiving a target grade request 205 from one or more of the user input interface 155 and a storage medium 125 may comprise an absolute value target grade request 250 where the user enters and establishes the target grade 205 to be established or alternatively a program mode 255 in which the user enters, programs, or establishes a guidance program in accordance with a predetermined sequence of inputs 260 from a storage medium 125. The predetermined sequence of inputs 260 may comprise of variable target grade requests corresponding to the desired topography outlined in program mode 255. The predetermined sequence of inputs 260 from the storage medium may be, for example, a series of target grade movements, the target grade within a specified location comprising one or more an x, y, and z direction. The target grade 205 may comprise one or more of maintaining a target height of the pivot axis 175, a target implement angle relative to the ground surface 115, or an absolute value acquired from a location-determining receiver 135. The target grade 205 may comprise one or more absolute elevations or real world elevations that (1) remain constant regardless of variation (e.g. natural variation) in the raw terrain (2) vary in accordance with a substantially linear grade, a substantially curved grade or a sloped planar surface according to a mathematical relationship. For example, a mild grade and even surface may be required when excavating trenches for pipelaying. In another example, a target grade may be required to create substantially sloped planar surfaces for directing precipitation runoff towards reservoirs. In surface mining, a consistent depth of surface removal is required.

FIG. 7 is flowchart of an algorithm for operating a boom assembly 163 and/or implement 185 with the control architecture 210 for the embodiment shown in FIG. 1.

Referring to FIGS. 3 and 4 with continued reference to FIG. 7, operating the first actuator 165 in automatic mode 220 may comprise moving the boom 160 upwards 740 when in step 730 i) the dipper stick is outside the pivot axis 405 and ii) the dipper stick 170 is arming in 245; moving the boom 160 upwards 740 when in step 750 i) the dipper stick is inside the pivot axis 410 and ii) the dipper stick 170 is arming away 240; moving the boom 160 downwards 770 in step 760 when i) the dipper stick is outside the pivot axis 405 and ii) the dipper stick is arming away 240; and moving the boom 160 downwards 770 in step 780 when i) the dipper stick is inside the pivot axis 410 and ii) the dipper stick is arming in 245.

In a first embodiment, the operator controls movement of the second actuator 180 through the user input interface 155, and upon entering the automatic control region 265, the controller 130 automatically responds in moving the pivot axis 175 by actuating the first actuator 165 to maintain the target grade 205 derived from the user input interface 155 or the storage medium 125. That is, the operator moves the boom 160 and/or implement 185 within the automatic control region 265 in one or more of an x, y, and z direction. The top portion of the frame 105 may swivel relative to the ground-engaging mechanism about the z-axis, as well. FIG. 6 is a top view schematic demonstrating a pre-defined automatic control region 265 (shown in the dotted lines) in an x-y direction.

The controller 130 may be further configured to deactivate automatic mode 220 of the first actuator when the dipper stick position and the direction of movement of the dipper stick are outside the automatic control region.

Now turning to FIG. 4A, arming in of the dipper stick may comprise of extension of the second actuator 180, whereby arming in 245 generally moves the dipper stick 170 and implement 185 coupled thereto towards the frame 105 of the excavator 100. In the exemplary embodiment, movement of arming in 245 is indicated by the arrow shown in FIG. 4A and the dipper stick 175 is shown inside the pivot axis. This arming in 245 movement may generally be associated with the dig cycle. The vertical line 420 is an imaginary vertical line (shown by the dotted line) from the pivot axis 175 to the ground surface 115. As discussed earlier, the height of pivot axis 175 relative to the ground surface 115 or frame 105 of the excavator 100 is controlled when in the automatics control region 265 to maintain the target grade 205. As the vertical line 420 traverses the direction of movement of the boom 160 changes direction.

Now turning to FIG. 4B, arming away 240 of the dipper stick 170 may comprise of retraction of the second actuator 180, whereby arming away 240 generally moves the dipper stick 170 and implement 185 coupled thereto away from the frame 105 of the excavator 100. In the exemplary embodiment, movement of arming away 240 is indicated by the arrow shown in FIG. 4B. This arming away 240 movement may generally be associated with the dump cycle. As previously mentioned, the vertical line 420 is an imaginary vertical line (shown by the dotted line) from the pivot axis 175 to the ground surface 115.

FIG. 3 is a side view schematic of an implement 185, demonstrating a pre-defined automatic control region 265 in an x-z direction. The control architecture 210 may be further configured to execute instructions to activate the third actuator 190 in automatic mode 220 to automatically curl 270 (shown by arrow) or dump 275 (shown by arrow) the implement 185 to adjust the angle α at which a cutting edge 200 of the implement engages the surface 115 (shown in FIG. 3), when the dipper stick 170 position and the direction 199 of movement of the dipper stick 170 are within the automatic control region 265, wherein the automatic mode 220 maintains a target grade 205. The curling 270 and dumping 275 may occur about the implement pivot axis 315. This control of the angle of the cutting edge 200 further refines precision of achieving of target grade 205 beyond mere implement height from the pivot axis 175. Angle α of implement 185 may activate if the cutting edge 200 enter or reside in the area between the upper threshold 305 and the lower threshold 310. An upper threshold 305 of an automatics control region 265 resides above the target grade 205. A lower threshold 310 of the lower automatics control region 265 resides below the target 205. In the embodiment depicted, the upper threshold 305 and the lower threshold 310 of the automatics control region 265 may have the same height with respect to the target grade 205. In other embodiments, the upper threshold 305 and the lower threshold 310 of the automatics control region 265 may have different heights with respect to the target grade 205

Operation of the third actuator 190 in automatic mode 220 may comprise dumping 275 the implement 185 when the dipper stick 170 is arming in 245 and curling the implement 270 when the dipper stick 170 is arming away 240.

The controller may further be configured to deactivate automatic mode of the third actuator 190 when the dipper stick position 230 and the direction of movement 235 of the dipper stick 170 are outside the automatic control region 265.

Now turning to FIG. 5, a first embodiment of a user input interface 155 for an excavator 100 is shown. The user input interface 155 may comprise of a first joystick 505 and a second joystick 510. The first joystick 505, on the left side of operator, may arm away 245 the dipper stick 170 when moved forward and may arm in 245 the dipper stick when moved backward. The second joystick 510, on the right side of the operator, may curl 270 the implement 185 when moving the second joystick 510 to the left and may dump 275 the implement 185 when moving the second joystick 510 to the right. The second joystick further 510 moves the boom 160 upwards when second joystick is moved forward and moves the boom 160 downwards when the second joystick is moved backwards. When using the above-mentioned control architecture 210, control of the boom assembly 163 becomes simplified, wherein manual control of the function of the second joystick 510 becomes automated when entering the automatics control region 265.

The terminology used herein is for the purpose of describing particular embodiments or implementations and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the any use of the terms “has,” “have,” “having,” “include,” “includes,” “including,” “comprise,” “comprises,” “comprising,” or the like, in this specification, identifies the presence of stated features, integers, steps, operations, elements, and/or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The references “A” and “B” used with reference numerals herein are merely for clarification when describing multiple implementations of an apparatus.

One or more of the steps or operations in any of the methods, processes, or systems discussed herein may be omitted, repeated, or re-ordered and are within the scope of the present disclosure.

While the above describes example embodiments of the present disclosure, these descriptions should not be viewed in a restrictive or limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the appended claims. 

What is claimed is:
 1. An excavator comprising: a frame; a ground-engaging mechanism coupled to the frame and configured to support the frame on a surface; a boom pivotally coupled to the frame; a first actuator interconnecting the boom and the frame and operable to move the boom relative to the frame; a dipper stick pivotally coupled to the boom for rotational movement about a pivot axis; a second actuator interconnecting the dipper stick and the boom and operable to move the dipper stick about the pivot axis relative to the boom; an implement pivotally coupled to the dipper stick; a third actuator interconnecting the implement and the dipper stick and operable to move the implement relative to the dipper stick; at least one sensor operable to sense one or more of a dipper stick position and a direction of movement of one or more of the boom, the dipper stick, or the implement; and a control architecture including: a user input interface, a storage medium having a control algorithm stored therein, and a controller configured to execute the control algorithm to: receive a target grade request from one or more of the user input interface and the storage medium; receive a dipper stick position relative to the pivot axis from the at least one sensor, wherein the dipper stick position is one of inside the pivot axis or outside the pivot axis; receive the direction of movement of the dipper stick relative to the pivot axis from the at least one sensor, wherein the direction of movement of the dipper stick is one of arming away from the pivot axis or arming toward of the pivot axis; and operating the first actuator in an automatic mode to automatically adjust a height of the pivot axis relative to the frame when the dipper stick position and the direction of movement of the dipper stick are within an automatic control region for automatically maintaining a target grade.
 2. The excavator of claim 1, wherein operating the first actuator in an automatic mode comprises: moving the boom upwards when i) the dipper stick is outside the pivot axis and ii) the dipper stick is arming in; moving the boom upwards when i) the dipper stick is inside the pivot axis and ii) the dipper stick is arming away; moving the boom downwards when i) the dipper stick is outside the pivot axis and ii) the dipper stick is arming away; and moving the boom downwards when i) the dipper stick is inside the pivot axis and ii) the dipper stick is arming in.
 3. The excavator of claim 1, wherein the controller is further configured to deactivate the automatic mode of the first actuator when the dipper stick position and the direction of movement of the dipper stick are outside the automatic control region.
 4. The excavator of claim 2, wherein the control architecture is further configured to execute instructions to: activate the third actuator in the automatic mode to automatically curl or dump the implement to adjust an angle a cutting edge of the implement engages the surface when the dipper stick position and the direction of movement of the dipper stick are within the automatic control region, the automatic mode maintaining the target grade.
 5. The excavator of claim 4, wherein operating the third actuator in the automatic mode comprises: dumping the implement when the dipper stick is arming in; and curling the implement when dipper stick is arming away.
 6. The excavator of claim 4, wherein the controller is further configured to deactivate the automatic mode of the third actuator when the dipper stick position and the direction of movement of the dipper stick are outside the automatic control region.
 7. The excavator of claim 1, wherein maintaining the target grade is sourced from feedback from one or more of a global positioning system and a positioning of the dipper stick relative to the frame.
 8. The excavator of claim 2, wherein arming in of the dipper stick comprises extension of the second actuator.
 9. The excavator of claim 2, wherein arming away of the dipper stick comprises retraction the second actuator.
 10. The excavator of claim 1, wherein the user input interface comprises: a first joystick and a second joystick, the first joystick arming away the dipper stick when moved forward and arming in the dipper stick when moved backward, and the second joystick curling the implement when moving the joystick to the left and dumping the implement when moving the joystick to the right.
 11. A method for controlling an excavator, the method comprising: enabling an automatic mode based on user input with a switch from a user input interface; receiving a target grade request from one or more of the user input interface and a storage medium; receiving a dipper stick position relative to a pivot axis from at least one sensor, wherein the dipper stick position is one or more of inside the pivot axis and outside the pivot axis; receiving a direction of movement of a dipper stick relative to the pivot axis from the at least one sensor, wherein the direction of movement of the dipper stick one of arming away from the pivot axis or arming toward the pivot axis; and activating the first actuator in the automatic mode to automatically adjust a height of the pivot axis relative to a frame based on the dipper stick position and the direction of movement of the dipper stick automatically maintaining a target grade.
 12. The method of claim 1, wherein operating the first actuator in the automatic mode comprises: moving a boom upwards when i) the dipper stick is outside the pivot axis and ii) the dipper stick is arming in; moving the boom upwards when i) the dipper stick is inside the pivot axis and ii) the dipper stick arming away; moving the boom downwards when i) the dipper stick is outside the pivot axis and ii) the dipper stick is arming away; and moving the boom downwards when i) the dipper stick is inside the pivot axis and ii) the dipper stick is arming in.
 13. The method of claim 11, further comprising: deactivating the automatic mode of a first actuator when the dipper stick position and the direction of movement of the dipper stick are outside an automatic control region.
 14. The method of claim 12 further comprising: activating the third actuator in the automatic mode to automatically curl or dump the implement to adjust the angle a cutting edge of the implement engages the surface, when the dipper stick position and the direction of movement of the dipper stick are within an automatic control region, the automatic mode maintaining a target grade.
 15. The method of claim 14, wherein operating the third actuator in the automatic mode comprises: dumping the implement when the dipper stick is arming in; and curling the implement when the dipper stick is arming away.
 16. The excavator of claim 14, wherein the controller is further configured to deactivate the automatic mode of the third actuator when the dipper stick position and the direction of movement of the dipper stick are outside the automatic control region.
 17. The method of claim 11, wherein maintaining a target grade is sourced from one or more of a global positioning system and the dipper stick position relative to the frame.
 18. The method of 12, wherein arming in of the dipper stick comprises extension of the second actuator.
 19. The method of claim 12, wherein arming away of the dipper stick comprises retraction of the second actuator.
 20. The method of claim 11, wherein the user input interface comprises: a first joystick and a second joystick, the first joystick arming away the dipper stick when moved forward and arming in the dipper stick when moved backward, and the second joystick curling an implement when moving the joystick to the left and dumping the implement when moving the joystick to the right. 